As a result of disease or injury, many people suffer from a loss of permanent teeth. In severe cases, the surrounding oral tissue may be damaged as well. The loss of permanent teeth frequently limits the person's ability to chew food and may also appear unsightly. To fill the gap left by the lost teeth and to improve the person's ability to chew food, a dental prosthesis may be installed through oral surgery.
Ideally, the dental prosthesis is attached to the surrounding teeth. However, in situations where this is not possible, a dental implant is. installed and the prosthesis is mounted to the implant. As depicted in FIG. 1, one type of prior known implant 10 consists of a mounting stud 12 attached to a substructure 14 that is implanted into the patient's upper or lower jaw, i.e., the mandibular or maxillary structures. In order for the prosthesis (not shown) to withstand the significant occlusal forces exerted during mastication, the substructure 14 to which it is attached must be rigidly fixed in the jaw. The substructure 14 typically consists of a relatively long screw-type support 16, which has threads 18 and is screwed deeply through the cortical bone section 20 and into the cancellous bone section 22 of the jaw. The mounting stud 12, which rigidly attaches to the substructure 14 protrudes above the gum line 24, permitting the attachment thereto of the dental prosthesis.
There are several risks and limitations inherent in the use of this type of dental implant. First, the installation of the substructure 14 results in significant trauma to the jaw bone and risk of infection, because of the amount of drilling needed to seat the long screw support 16. Second, installation of the long screw support 16 risks damage to the mandibular nerve 26 which runs through the cancellous bone section 22 of the jaw or perforating the cancellous bone section 22. To minimize the risk of injury to the mandibular nerve 26 or of perforating the cancellous bone section 22 and to ensure adequate rigidity of the eventual prosthesis, the procedure is performed only if sufficient bone structure exists. Unfortunately, many patients lack the requisite bone structure in the area of the proposed prosthesis and are thus precluded from having this type of dental implant installed. As a result, these patients may be forced to undergo even greater reconstructive surgery, or forego a dental prosthesis altogether.
In addition to the above-referenced risks, expensive equipment that is suited only for the installation of these devices must be acquired. In particular, a drill that corresponds to the non-standard dimensions of the particular screw-type support being installed must be used to drill the necessary hole in the patient's jaw. Furthermore, a unique hand-piece is often required to install the screw support, which may have a non-standard head. As a result, the costs associated with installing a screw-type of implant can be significant.